中国科学院机构知识库网格系统: 检索

High peak power sub-nanosecond mode-locked pulse characteristics of Nd:GGG laser 期刊论文 OAI收割
optics and laser technology, 2015, 卷号: 73, 页码: 162-165
作者: Zhao, Jia; Zhao, Shengzhi; Li, Tao; Li, Yufei; Yang, Kejian

收藏 | 浏览/下载：27/0 | 提交时间：2015/09/09

Nd:GGG crystal High peak power Sub-nanosecond pulse width

Study of Point Spread in the Aberration-Corrected Transmission Electron Microscopy 期刊论文 OAI收割
MICROSCOPY AND MICROANALYSIS, 2014, 卷号: 20, 期号: 5, 页码: 1447
Ge, BH; Wang, YM; Chang, YJ; Yao, Y

收藏 | 浏览/下载：24/0 | 提交时间：2015/04/14

point spread peak width aberration-corrected transmission electron microscopy quantitative electron microscopy negative C-s imaging positive C-s imaging

Improved method of target detection on optoelectronic hybrid joint transform correlator in cluttered scences (EI CONFERENCE) 会议论文 OAI收割
2011 3rd International Conference on Mechanical and Electronics Engineering, ICMEE 2011, September 23, 2011 - September 25, 2011, Hefei, China
作者: Yang L.; Yang L.

收藏 | 浏览/下载：22/0 | 提交时间：2013/03/25

A classical joint transform correlator (JTC) usually yields large correlation sidelobes as well as a large correlation peak width strong zero-order peak and low diffraction efficiency which make the detection ability of JTC lower. To overcome these difficulties firstly a joint power spectrum (JPS) subtraction technique in Fourier plane was proposed where reference image power spectrum and object image power spectrum are subtracted from the JPS before inverse Fourier-transform operation it is obvious that the modified JPS removes the zero-order term. Secondly a fringe-adjusted filter (FAF) was presented to suppress sidelobes and noises. The modified JPS is multiplied by a FAF before the inverse Fourier-transform operation to obtain the cross-correlation peak. Computer simulations demonstrated the improved method can obviously remove zero-order diffraction and effectively suppress the sidelobes and noises compared with classic JTC and then improve the detection ability for JTC. Experimental results presented the sharp correlation peak and also confirmed the method effectiveness. (2012) Trans Tech Publications Switzerland.

Effect of thickness on the structural, electrical and optical properties of ZnO films deposited by MBE (EI CONFERENCE) 会议论文 OAI收割
2011 International Conference on Advanced Design and Manufacturing Engineering, ADME 2011, September 16, 2011 - September 18, 2011, Guangzhou, China
Yang X.; Su S.; Yi X.; Mei T.

收藏 | 浏览/下载：25/0 | 提交时间：2013/03/25

A set of ZnO films of different thickness have been deposited on sapphire substrates using molecular beam epitaxy (MBE) by varying the growth time and the effect of film thickness on the structural electrical and optical properties have been investigated. The X-ray diffraction (XRD) results indicate that the full width at half maximum (FWHM) of the (002) diffraction peak is decreased as the film thickness increasing and the stress along c-axis is stable. Scanning electron microscope (SEM) measurement shows that the grains become more uniform as the film grows thicker and the film surface present distinct hexagon shape as the film is grown up to a thickness of 500nm. The optical absorbance Hall mobility and photoluminescence (PL) intensity are increased in accordance with the thickness of the film. (2011) Trans Tech Publications Switzerland.

ZnO thin film grown on glass by metal-organic chemical vapor deposition (EI CONFERENCE) 会议论文 OAI收割
2008 2nd IEEE International Nanoelectronics Conference, INEC 2008, March 24, 2008 - March 27, 2008, Shanghai, China
作者: Wang C.

收藏 | 浏览/下载：157/0 | 提交时间：2013/03/25

ZnO thin film was deposited on the substrate of Corning glass by metal-organic chemical vapor deposition (MOCVD)[1 2 3] with a buffer layer of SiNx grown by plasma enhanced chemical vapor deposition. The quality of ZnO film was studied by X-ray diffraction and photoluminescence measurement. We found strong diffraction (0 0 2) peak at 34.50 indicating that the ZnO film was strongly C-oriented. The full-width at half maximum of (0 0 2) peak was 0.179. 2008 IEEE.

Effect of interface on luminescence properties in ZnO/MgZnO heterostructures (EI CONFERENCE) 会议论文 OAI收割
Wei Z. P.; Lu Y. M.; Shen D. Z.; Wu C. X.; Zhang Z. Z.; Zhao D. X.; Zhang J. Y.; Fan X. W.

收藏 | 浏览/下载：30/0 | 提交时间：2013/03/25

A set of ZnO/MgZnO heterostructures with well widths Lw varying from 2 to 20 nm has been grown by plasma-assisted molecular-beam epitaxy (P-MBE). We present a room-temperature (RT) study of the well-width-dependent photoluminescence (PL) spectra and carrier lifetimes in ZnO/MgZnO heterostructures. Bi-exponential process is seen at RT time-decay curves of the luminescence from the well layers. The fast process is from the recombination of the free exciton while the slow process is attributing to the recombination of the localized exciton in the interface of ZnO and MgZnO. It is also confirmed from the PL peak shift of time-resolved PL spectra. With decreasing the well thickness the fast process gradually increases and dominantly contributes to the PL spectrum due to the interface improvement. 2006 Elsevier B.V. All rights reserved.

Investigation of growth mode in ZnO thin films prepared at different temperature by plasma-molecular beam epitaxy (EI CONFERENCE) 会议论文 OAI收割
13th International Conference on Molecular Beam Epitaxy, August 22, 2004 - August 27, 2004, 13th International Conference on Molecular Beam Epitaxy, August 22, 2004 - August 27, 2004
Liang H. W.; Lu Y. M.; Shen D. Z.; Yan J. F.; Li B. H.; Zhang J. Y.; Liu Y. C.; Fan X. W.

收藏 | 浏览/下载：37/0 | 提交时间：2013/03/25

High-quality ZnO thin films on c-plane sapphire (Al2O 3) substrates were prepared by plasma-molecular beam epitaxy (P-MBE). The influence of growth temperature on growth mode of ZnO was investigated. Real-time monitored by reflection high-energy electron diffraction (RHEED) images show that below 500 C ZnO thin film was grown by three-dimension (3D) growth mode. While the two-dimension (2D) growth mode was obtained above growth temperature of 650 C. Atomic force microscopy (AFM) images present that the surface morphology of ZnO thin film with 2D growth is improved and X-ray rocking curves (XRC) indicate that the full width at half maximum (FWHM) of the ZnO (0 0 2) peak becomes narrow. From the photoluminescence (PL) spectra ultraviolet (UV) emission peak exhibits obvious blue-shift for the samples grown at lower temperature which is attributed to the effect of the quantum confinement arisen from small crystal grain sizes. The minimum carrier concentration of N=7.661016 cm-3 was obtained in the ZnO thin films with the 2D grown which is closed to that of bulk ZnO. 2005 Elsevier B.V. All rights reserved.

High-power InGaAs/GaAs VCSEL's two-dimension arrays (EI CONFERENCE) 会议论文 OAI收割
ICO20: Lasers and Laser Technologies, August 21, 2005 - August 26, 2005, Changchun, China
作者: Liu Y.; Wang L.-J.; Wang L.-J.; Liu Y.; Liu Y.

收藏 | 浏览/下载：26/0 | 提交时间：2013/03/25

Selectively oxidized InGaAs/GaAs vertical -cavity surface-emitting lasers (VCSEL) array at an emission wavelength of 980nm was reported. A 16 elements array with 200m aperture size (250m center spacing) of individual elements shows a CW output power of 1.21 W at room temperature resulting in 1 KW/cm2 average optical power density. The device threshold current is 1.32A The lasing peak wavelength is 981.9 nm the full width at half-maximum is 0.7 nm and the far-field divergence angle is about 17.The characteristics of a single device with a active region diameter of 800m is compared with that of a 2-D array with active region diameter of individual clement of 200m. These two kinds of devices have the same total lasing area. At the same current injection the single device has a higher threshold and a higher output power than the array. The red shift of single device is more obvious than that of the array's.

Phase-shifting apodizer for next-generation digital versatile disk 期刊论文 OAI收割
opt. eng., 2001, 卷号: 40, 期号: 6, 页码: 991, 994
Wang HF; Chen ZY; 干福熹

收藏 | 浏览/下载：2422/234 | 提交时间：2009/09/22

depth of focus axial intensity distribution half-width-ratio (HWR) center-peak-intensity ratio

New approach to superresolution 期刊论文 OAI收割
opt. eng., 2001, 卷号: 40, 期号: 5, 页码: 851, 855
Wang HF; 干福熹

收藏 | 浏览/下载：1461/235 | 提交时间：2009/09/22

superresolution spatial frequency half-width ratio center-peak intensity ratio relative sidelobe peak intensity